Can asbestos be used “safely”?

Our new blog ‘Science-ish’ considers the evidence

Photograph by Flickr user shaymus22

The Statement: “All scientific reviews clearly confirm that chrysotile [white asbestos] fibres can be used safely under controlled conditions.” (Dimitri Soudas, PMO communications director, 06/15/2011)

Chrysotile, or white asbestos, is back in the news again, and doctors around the world are questioning the Canadian government’s championing of a substance that has been banned in most developed countries. “My jaw dropped when I heard [Soudas’ statement],” says Dr. Matthew Stanbrook, a specialist in respirology at Toronto’s University Health Network and assistant professor in the department of medicine at the University of Toronto. “It’s so completely misrepresentative of the science.”

The term “asbestos” refers to two types of naturally occurring fibrous minerals: serpentine and amphibole. Chrysotile, derived from serpentine minerals, makes up 100% of the asbestos used and produced in the world today and 95% of all the asbestos used worldwide since 1900. It’s also the stuff Canada produces, alongside such countries as Kazakhstan, China, Brazil, and Russia.

Though there has been some debate about whether chrysotile is less hazardous than other forms of asbestos, the World Health Organization (WHO) is one of many international bodies which doesn’t discriminate among types of the mineral in discussing its dangers. “All forms of asbestos are carcinogenic to humans, and may cause mesothelioma and cancer of the lung, larynx and ovary,” the organization has concluded, estimating that about 125 million people in the world are exposed to asbestos in the workplace, and that each year, more than 107,000 people die from asbestos-related lung cancer, mesothelioma and asbestosis resulting from occupational exposure. They also estimate that one in three deaths from occupational cancer is caused by asbestos.

As for Soudas’ claim that it’s safe to use white asbestos in controlled conditions, a recent article on asbestos in the journal Environmental Health Perspectives noted: “Numerous epidemiologic studies, case reports, controlled animal experiments, and toxicological studies refute the assertion that chrysotile is safe. […] These studies demonstrate that the so-called controlled use of asbestos is a fallacy.”

Science-ish contacted the Quebec-based IRSST (Robert-Sauvé Occupational Health and Safety Research Institute) to get their view. A spokesperson said, “All the studies we know of tend to show that all types of asbestos fibres have adverse effects on health.” They cite the findings of a scientific working group brought together by the International Agency for Research on Cancer in March 2009, which concluded there is a link between all forms of asbestos (including chrysotile) and an increased risk of lung cancer and mesothelioma. They added: “Although the potency differences with respect to lung cancer or mesothelioma for fibres of various types and dimensions are debated, the fundamental conclusion is that all forms of asbestos are carcinogenic to humans.”

In Canada, asbestos remains one of the leading causes of lung cancer, according to the Lung Cancer Association, up there with smoking and exposure to second-hand smoke and radon.

In 2006, the WHO said that if a global ban on asbestos were enacted, a decrease in the incidence of asbestos-related diseases would surface approximately 20 years later, adding that “the most efficient way to eliminate asbestos-related diseases is to stop using all types of asbestos.” The International Labour Organization also passed a resolution to promote a worldwide asbestos ban.

Such bans require some international consensus, though, and Canada has twice blocked even the inclusion of chrysotile on a list of hazardous substances under the United Nations Rotterdam Convention, which regulates the global trade of certain hazardous chemicals and requires countries that import the substances to give “prior informed consent” that they are aware of the hazards associated with them. Canada is expected to do so again at the Rotterdam Convention in Geneva on Monday.

Julia Belluz is the associate editor at The Medical PostSeen something that’s Science-ish? Email her at [email protected].

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